A new titanosaur (Dinosauria,Sauropoda) from the Upper Cretaceous of Lo Hueco (Cuenca,Spain)

The upper Campanian-lower Maastrichtian site of Lo Hueco (Cuenca, Spain) has provided a set of well-preserved partial skeletons in anatomical connection or with a low dispersion of their skeletal elements. One partial skeleton is herein described and a new titanosaurian sauropod is established, Lohuecotitan pandafilandi. This titanosaur is diagnosed by eight autapomorphic features: dorsally and ventrally widened or bifurcated posterior centrodiapophyseal lamina in anterior and middle dorsal vertebrae; short postspinal lamina with a transversely expanded distal end represented by smooth scars in the dorsal vertebrae; anteriormost caudals with the medial spinoprezygapophyseal and medial spinopostzygapophyseal laminae ventrally connected with the prespinal and postspinal laminae, respectively; anterior caudal neural spines with a dorsal projection of the prespinal and postspinal laminae; anterior caudal neural spines bears a “greek-cross”-like cross-section; middle caudal centra having two round and rough structures in the dorsal edge of the posterior articulation, which extends to the dorsal surface of the centrum; the articular ends of the rami of the haemal arches are divided in two articular surfaces; and tuberosity between the anterior and the lateral trochanter of the fibula. The herein performed phylogenetic analysis considered L. pandafilandi as a member of Lithostrotia more derived than Malawisaurus. The known palaeodiversity of the Late Cretaceous Ibero-Armorican titanosaurs is increasing, and further analyses focused on this group will be necessary to better understand the evolutionary history of European titanosaurs and to clarify their relationships within Titanosauria.     

The axial skeleton of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the latest Cretaceous of Spain

Lirainosaurus astibiae was originally described by Sanz and collaborators in 1999 on the basis of a skull fragment, isolated teeth, several vertebrae (e.g. the holotypic anterior caudal vertebra) and appendicular bones from the Late Cretaceous of Laño (northern Spain). A review of all the vertebral remains, including new material (cervical, dorsal and caudal vertebrae, dorsal ribs, haemal arch), provides additional information about the axial skeleton of Lirainosaurus. A study of the laminae and fossae shows interesting variations in these structures in the axial series, especially concerning the prezygapophyses and diapophyses: e.g. the X-shaped morphology of the centroprezygapophyseal lamina only in the posterior dorsal vertebrae, and the division of the postzygodiapophyseal fossa into two fossae in the posterior dorsal vertebrae and the proximal caudal vertebrae. Two vertebral characters are here considered to be autapomorphic for L. astibiae: the presence of a lamina in the interzygapophyseal fossa in the most proximal caudal vertebrae (a postzygodiapophyseal lamina that separates the ventral postzygapophyseal centrodiapophyseal fossa and the dorsal postzygapophyseal spinodiapophyseal fossa), and the spinopostzygapophyseal structure not posteriorly projected in the posterior caudal vertebrae. The combination of characters present in the axial remains of Lirainosaurus astibiae supports the idea that it is a derived lithostrotian close to Saltasaurinae.     

Taxonomy, facies relationships and palaeobiology of bakevelliid bivalves from the Lower Cretaceous of west-central Argentina

Cretaceous bakevelliids in Argentina are restricted to the Lower Cretaceous. They are recorded in shallow marine deposits in two Mesozoic basins located in the Andes foothills in Patagonia. In the Austral Basin (44°–55°S) there is only one genus, Gervillella, represented by a single specimen from the Barremian. In the Neuquén Basin (30°–40°S) two genera, Gervillaria and Gervillella, occur, ranging from the Berriasian to the Lower Barremian. In the Pilmatué Member of the Agrio Formation two species are identified: Gervillaria alatior (Imlay) and Gervillella aviculoides (J. Sowerby). The former is also recorded in Mexico while the latter is more widespread, occurring in Europe, Asia, and Africa. In the Bajada del Agrio section they come from eight tabular shell beds located near and on top of shallowing-upwards cycles. They were abundant only in four of these levels. These shell beds are interpreted as having been deposited in the mid-ramp (middle of cycles), and upper mid-ramp (top of cycles). A functional analysis of shells revealed two life habits: epibyssate and endobyssate.     

山东晚白垩世一新的巨龙类恐龙

记述了产自山东诸城上白垩统王氏群中一个较完整的蜥脚类恐龙肱骨(ZJZ-57)。它具有一些进步特征,如肱骨三角胸嵴向远端扩展,肱骨近端外侧1/3处发育隆凸,表明其属于较进步的巨龙类成员。另外,它具有一些独特的鉴定特征组合区别于其他任何巨龙类:近端横向强烈扩展,近端最大宽度与骨干长度之比为0.55;骨干粗壮,粗壮指数为0.39。综合研究表明,ZJZ-57所属个体代表了一种新的巨龙类恐龙:臧家庄诸城巨龙(Zhuchengtitan zangjiazhuangensis gen.et sp.nov.),它可能与Opisthocoelicaudia的亲缘关系较接近。这是山东晚白垩世地层中首次发现的巨龙类恐龙。     

Multiple neoplasms in a single sauropod dinosaur from the Upper Cretaceous of Brazil

Tumors are thought rare in dinosaurs, previously limited in distribution to a single family – hadrosaurs. Here we recognized two different neoplastic lesions, osteoma and hemangioma, in a single caudal vertebra of a titanosaur dinosaur from the Upper Cretaceous of Brazil, diagnosed on the basis of macroscopic, radiological and histological analysis. This is the first occurrence of neoplasia in a non-hadrosaur dinosaur. Therefore, neoplasia is not restricted to hadrosaur dinosaurs, as previously suggested.     

First record of a clupeomorph fish in the Neuquén Group (Portezuelo Formation), Upper Cretaceous of Patagonia, Argentina

A new genus and species of clupeomorph fish, Leufuichthys minimus, is described from the fluvial deposits of the Portezuelo Formation, Upper Cretaceous (Turonian-Coniacian) of the Neuquén Group, Patagonia, Argentina. It is a small-sized fish with an estimated body length up to 46 mm. Among other characters, the new species shows the following: abdominal scutes; abdomen moderately convex; anal fin elongate-based; three uroneurals; two epurals; caudal fin bearing very elongate rays; and cycloid scales. Leufuichthys minimus gen. et sp. nov. shows a greater similarity with Kwangoclupea dartevellei, a clupeomorph described from a marine Cenomanian deposit of the Democratic Republic of Congo (Africa), mainly due to the presence of an elongate-based anal fin, bearing more than 20 fin-rays, differing from it by the presence of a not hypertrophied abdomen. As far as known, L. minimus gen. et sp. nov. is the first clupeomorph described in the Upper Cretaceous of Patagonia and represents one fortuitous preservation of an articulated fish in fluvial deposits.     

A new Late Cretaceous crocodyliform from the western margin of Gondwana (La Rioja Province,Argentina)

The Cretaceous witnessed the greatest diversity of Gondwanan notosuchian crocodyliforms, which displayed high levels of diversity and a notable array of specialized forms that developed in different ecological niches. Among this diversity, the advanced notosuchians are a clade of mid body sized forms which displays a remarkable abundance but is restricted to two lithological units from the Late Cretaceous of South America, the Adamantina Formation in southeastern Brazil and the Bajo de la Carpa Formation in Patagonia (Argentina). The only exceptions known so far were the Late Cretaceous Labidiosuchus from the Marilia Formation in Brazil and Yacarerani from the Cajones Formation in Bolivia. Herein we report a new Cretaceous crocodyliform, Llanosuchus tamaensis gen. nov. et sp. nov., found in the Los Llanos Formation (Campanian?) in northwestern Argentina (La Rioja Province). The small specimen includes well preserved fragments of the cranium and mandible with an estimated skull size of about 9 cm lengths. This crocodyliform shares several derived characters with Notosuchus terrestris from the Bajo de la Carpa Formation (Patagonia) and it was found in a weakly developed sandy paleosol profile formed in wet local conditions but in a region characterized by semi-arid climate and active eolian sedimentation. The presence of a new advanced notosuchian in the Cretaceous of western Gondwana, and its intermediate geographical region between the known South American species (Brazil, Argentina and Bolivia), has interesting implications, and adds another record of an advanced notosuchian in deposits with inferred warm climates and semi-arid paleoenvironments. Finally, Llanosuchus tamaensis supports a Late Cretaceous age for Los Llanos Formation with important geological implications for La Rioja Province.     

Aeolian/fluvial interactions and high-resolution sequence stratigraphy of a non-marine lowstand wedge: the Avilé Member of the Agrio Formation (Lower Cretaceous), central Neuquén Basin, Argentina

Abstract Accumulation within the unconformity‐based Hauterivian Avilé Sandstone of the Neuquén Basin, Argentina, was characterized by a close interaction between fluvial and aeolian processes developed after a major relative sea‐level drop that almost completely desiccated the entire basin and juxtaposed these non‐marine deposits on shallow‐ and deep‐marine facies. Aeolian deposits within the Avilé Member include dune (A1) and sand sheet (A2) units that characterize the lower part of the unit. Fluvial deposits comprise distal flood units (F1) interbedded with aeolian dune deposits in the middle part of the succession, and low‐ (F2) and high‐sinuosity (F3) channels associated with floodplain deposits (F4) towards the top. The internal characteristics of the aeolian system indicate that its accumulation was strongly controlled by water‐table dynamics, with the development of multiple horizontal deflation super surfaces that truncate dune deposits and form the basal boundary of flood deposits and sand sheet units. A long‐term wetting‐upward trend is recorded throughout the entire unit, with an increase in fluvial activity towards the top and the development of a more permanent fluvial system overlying a major erosion surface interpreted as a sequence boundary. The upward increase in water‐table influence might be related to relative sea‐level rise, which controlled the position of the water table and allowed the accumulation of tabular aeolian units bounded by horizontal deflation surfaces. This high‐frequency, eustatically driven process acted together with a long‐term climatic change towards wetter conditions.     

Preservation of borings: contrasting examples from the type Maastrichtian (Upper Cretaceous), southern Limburg,the Netherlands

The taphonomy of trace fossils and their substrates remains an understudied facet of sedimentary geology. Contrary to common prejudice, trace fossils are not invariably preserved in situ, but may be exhumed and reworked following lithification. The trace fossils most commonly found ex situ are borings in mobile shelly substrates. Two notable, but contrasting, examples of post-mortem transport of borings are described from the Maastrichtian (Upper Cretaceous) of southern Limburg, the Netherlands. A long, unusually straight and complete calcareous tube assigned to Teredolites longissimus Kelly and Bromley is an organically secreted internal mould, produced by a teredinid or pholadid bivalve boring in wood and lining their tube. Strictly, this is part of the body fossil of the producing bivalve, but it is also an organically generated internal mould of the boring. A flint steinkern of a right valve of Crassatella bosquetiana d’Orbigny preserves a suite of silicified borings. Caulostrepsis taeniola Clarke is a U-shaped boring with a vane connecting the parallel limbs. Talpina isp. is a slender, simple, branched tunnel. Most unexpected, Spirichnus spiralis Fürsich et al. is a spiral ‘worm’ boring hitherto only known from the Upper Jurassic. This stratigraphic gap is likely an artefact; only mouldic preservation of the bored substrate would expose the distinctive Spirichnus boring. These ichnofossils are united in their occurrence in unusual preservational systems.     

Construction of a fluvial facies knowledge graph and its application in sedimentary facies identification

Lithofacies paleogeography is a data-intensive discipline that involves the interpretation and compilation of sedimentary facies. Traditional sedimentary facies analysis is a labor-intensive task with the added complexity of using unstructured knowledge and unstandardized terminology. Therefore, it is very difficult for beginners or non-geology scholars who lack a systematic knowledge and experience in sedimentary facies analysis. These hurdles could be partly alleviated by having a standardized, structured, and systematic knowledge base coupled with an efficient automatic machine-assisted sedimentary facies identification system. To this end, this study constructed a knowledge system for fluvial facies and carried out knowledge representation. Components include a domain knowledge graph for types of fluvial facies (meandering, braided and other fluvial depositional environments) and their characteristic features (bedforms, grain size distribution, etc.) with visualization, a method for query and retrieval on a graph database platform, a hierarchical knowledge tree-structure, a data-mining clustering algorithm for machine-analysis of publication texts, and an algorithm model for this area of sedimentary facies reasoning. The underlying sedimentary facies identification and knowledge reasoning system is based on expert experience and synthesis of publications. For testing, 17 sets literature publications data that included details of sedimentary facies data (bedforms, grain sizes, etc.) were submitted to the artificial intelligence model, then compared and validated. This testing set of automated reasoning results yielded an interpretation accuracy of about 90% relative to the published interpretations in those papers. Therefore, the model and algorithm provide an efficient and automated reasoning technology, which provides a new approach and route for the rapid and intelligent identification of other types of sedimentary facies from literature data or direct use in the field.     

塔里木盆地西南地区白垩系沉积相特征

塔西南白垩系发育,可分为上、下两统。下白垩统克孜勒苏群可分4段,多以陆相沉积为主,富含棕红色砂砾岩夹少许砂岩、粉砂岩、泥岩和砾岩。上白垩统英吉沙群为海陆相并存,库克拜组可分2段,常见泥岩、膏岩和海相化石;乌依塔格组多为红色泥岩、泥质粉砂岩夹砂岩;依格孜牙组多见灰岩、白云质灰岩,富含海相化石;吐依洛克组为棕红色泥岩、石膏和砂、砾岩,含海相化石。通过勾勒9个岩性单元的沉积相展布,分析昆仑山前白垩纪的沉积环境演化过程。克孜勒苏群西区多为陆相快速堆积,东区远离陆源为三角洲和滨岸沉积,具有宽泛的冲积扇—辫状河三角洲相分布。库克拜组总体显示为辫状河三角洲—潮坪相变的过程;乌依塔格组以潮坪为主;依格孜牙组表现为碳酸盐岩台地—台地边缘的演化;吐依洛克组为宽广潮坪。     

Evolution of Mesozoic fluvial systems along the SE flank of the West Siberian Basin, Russia

The Mesozoic stratigraphy in the subsurface of the West Siberian Basin contains prolific hydrocarbon accumulations, and thus the depositional environments of marine and marginal marine Jurassic and Cretaceous age sediments are well-established. However, no information is currently available on strata of equivalent age that crop out along the SE basin margin in the Mariinsk–Krasnoyarsk region, despite the potential of these exposures to supply important information on the sediment supply routes into the main basin. Detailed sedimentological analysis of Jurassic–Cretaceous clastic sediments, in conjunction with palaeo-botanical data, reveals five facies associations that reflect deposition in a range of continental environments. These include sediments that were deposited in braided river systems, which were best developed in the Early Jurassic. These early river systems infilled the relics of a topography that was possibly inherited from earlier Triassic rifting. More mature fluvial land systems evolved in the Mid to Late Jurassic. By the Mid Jurassic, well-defined overbank areas had become established, channel abandonment was commonplace, and mudrocks were deposited on floodplains. Coal deposition occurred in mires, which were subject to periodic incursions by crevasse splay processes. Cretaceous sedimentation saw a renewed influx of sand-grade sediment into the region. It is proposed that landscape evolution throughout the Jurassic was driven simply by peneplanation rather than tectonic processes. By contrast, the influx of sandstones in the Cretaceous is tentatively linked to hinterland rejuvenation/ tectonic uplift, possibly coeval with the growth of large deltaic clinoform complexes of the Neocomian in the basin subsurface.     

New record of titanosaurian (Dinosauria: Sauropodomorpha) osteoderms from the Upper Cretaceous of North Patagonia

The idea that titanosaurs had osteoderms was proposed in the late nineteenth century by Depéret. However, this idea was given little credence by other researchers until 1980 when unequivocal evidence of armoured titanosaurs was reported. Since then, many discoveries of titanosaurian osteoderms have been made worldwide. In this work, seven osteoderms are described from the Allen Formation (upper Campanian–lower Maastrichtian), Salitral Moreno locality, Río Negro Province, Argentina. Among the described osteoderms it was possible to recognize three morphologies (keeled, ellipsoidal and cylindrical), with the first of these being most prevalent. Although the osteoderms from Salitral Moreno resemble osteoderms found in other parts of the world, no osteoderms of a similar morphotype are known from this locality, or from Lago Pellegrini or Cinco Saltos.     

Orkoraptor burkei nov. gen. et sp., a large theropod from the Maastrichtian Pari Aike Formation, Southern Patagonia, Argentina

A new large theropod, Orkoraptor burkei nov. gen. et nov. sp., from the Upper Cretaceous (Maastrichtian) Pari Aike Formation of southern Patagonia is based on a postorbital, quadratojugal, coronoid?, several teeth, an atlantal intercentrum and neurapophysis, two caudal vertebrae, and the proximal half of tibia. This new theropod exhibits characteristics of maniraptorans (i.e., coelurosaurians more derived than tyrannosaurids) including an upturned rostral process of the postorbital, the caudoventral corner of which is widely concave. Furthermore, teeth without denticles and carina in the mesial margin resemble the condition of the maniraptoran clades Compsognathidae and Deinonychosauria. The new Patagonian theropod differs from other coelurosaurians (Ornithomimosauria, Compsognathidae, Alvarezsauridae, Dromaeosauridae, Aves) in having caudal vertebrae with a single pair of small pleurocoels on each side, and in having a median depression flanked by two longitudinal and narrow furrows on each tooth. Orkoraptor represents one of the southernmost carnivorous dinosaurs yet found in South America and adds valuable information about the diversification of tetanuran theropods in Gondwana.     

A new titanosaur from the Lower Cretaceous of Brazil

Here we describe a new record of a sauropod dinosaur from the Lower Cretaceous (Hauterivian–Barremian) Rio Piranhas Formation, Sousa Basin, NE Brazil. Dinosaur fossil bones from this deposit were unknown until now. Thus, the discovery of a sauropod fibula from this locality is highly significant. Our discovery represents an indeterminate titanosaur and the earliest stratigraphic occurrence of this group in central Gondwana. When compared to chronocorrelate titanosaur trackmakers of this geological unit, this fossil specimen appears substantially smaller. Histological analysis of the fibula suggests that this is a relatively young individual (approximately 40–50% adult body size) that had passed its most rapid phase of early juvenile growth, but had not yet attained somatic maturity. Thus, the fibula recovered is from a young individual rather than from a small-bodied adult titanosaur.     

准噶尔盆地石南31井区下白垩统清水河组一段辫状河三角洲相及沉积演化

针对准噶尔盆地腹部石南31井区下白垩统清水河组一段三角洲相沉积的不同认识,根据砾岩的成层性、组构、结构成熟度、孔隙发育等特征,以及砂岩的结构、构造、粒度特征、砂体的空间展布特征,笔者认为清水河组一段是较强水动力条件下牵引流沉积的产物,其沉积环境属辫状河三角洲。通过对岩心的详细观察与描述,结合测井相分析,以石南31井区211口井的单井相分析为基础,依据连井相剖面分析和平面沉积相综合研究,认为该区辫状河三角洲的各亚相发育齐全,并识别出了辫状河道、河漫、水下分流河道、支流间湾、河口砂坝、远砂坝、前三角洲泥、前三角洲沟道砂等微相。在清一段早期（K₁q²₁）,研究区以湖泊相沉积为主,仅东南部为辫状河三角洲沉积。其后,研究区南北两个方向的辫状河三角洲相向推进（K₁q^1-3-4₁ 、K₁q^1-3-3₁）;继而,东南部的辫状河三角洲平原消失,研究区内仅见三角洲前缘（K₁q^1-3-2₁）沉积;K₁q^1-3-1₁沉积时期以细粒沉积为主,而沉积相格局则大致同前。同样,K₁q^1-2₁沉积时期,北方发育辫状河三角洲平原及前缘,东南方仅发育三角洲前缘。清一段晚期（K₁q^1-1₁）,由于湖平面快速上升,全区均演化为前辫状河三角洲亚相,主要由前三角洲泥构成,并且发育条带状分布的沟道砂沉积。     

A New Basal Titanosaur (Dinosauria: Sauropoda) from the Early Cretaceous of China

A new dinosaur of Early Cretaceous age was recently discovered from the Mazongshan area of northwestern Gansu Province, China. The new dinosaur represents a new genus and species of Sauropoda, and is among the most basal members of Titanosauria. Its finding also suggests that titanosaurs might have originated in Asia no later than the Early Cretaceous.     

New materials of lithostrotian titanosaurs (Dinosauria: Sauropoda) from the Upper Cretaceous of central Patagonia

Continental Cretaceous deposits exposed in central Patagonia, Argentina, preserve a rich and important record of titanosaurian evolution that spans the entire Upper Cretaceous. Recently, a new lithostragraphic unit, the Lago Colhué Huapi Formation (Coniacian – Maastrichtian), was located in the Golfo San Jorge Basin. Here, we describe new titanosaurian sauropod material from that formation (UNPSJB-Pv 1051). The material consists of a partially articulated left hind limb and disarticulated but associated skeletal elements. They are confidently referred to Titanosauria, and within that clade, to Lithostrotia, probably occupying a derived position. We interpret the bone concentration as an assemblage of hydraulic origin deposited in a fluvial channel. This new material begins the incipient fossil record of the Lago Colhué Huapi Formation, thereby also increasing the titanosaurian diversity of the latest Cretaceous. Additionally, the new titanosaurian enhances evidence in support of strong faunal similarities among the Allen and Marilia formations, chronological equivalents in the Cretaceous of South America. Furthermore, the Lago Colhué Huapi specimen adds to the Late Cretaceous record of Titanosauria and augments our knowledge of central Patagonian terrestrial vertebrate assemblages during this interval.     

藏南晚白垩世旋回地层学研究:以定日贡扎剖面为例

旋回地层学是提高地质年代标尺精度的一种重要方法。特提斯海相沉积是旋回地层学研究的良好对象,与西特提斯比较,东特提斯的旋回地层学研究程度较低,第四纪之前的研究精确度有待进一步的提高。西藏南部广泛出露海相白垩系,其中定日贡扎剖面出露的上白垩统尤为连续和完整。在对贡扎剖面野外观察及其层束厚度测量的基础上,通过快速傅立叶变换(FFT),分析该地层蕴含的地球轨道周期,得到了与理论值较为接近的结果:偏心率周期,4092 ka/周期(E1),1279 ka/周期(E2),93 ka/周期(E5);斜率周期,512 ka/周期(O1),409 ka/周期(O2),389 ka/周期(O2)。在功率谱分析过程中,利用层束和超层束组的关系进行了调谐的处理,并比较调谐前后结果,来确定调谐的重要性,证明该地层沉积速率的变化:地层由老至新,其沉积速率的变化趋势整体为由小变大,变化范围为086～253 cm/ka。进一步对比东西特提斯和其他地区研究结果,证明东西特提斯海相沉积在外形、成因和所蕴含的轨道周期的一致性,地球轨道周期变长与理论值变化的一致性。最后给出了下一步工作的建议。 关键词：藏南; 定日; 晚白垩世; Coniacian阶; 旋回地层学     

A Titanosaurian Sauropod Dinosaur with Opisthocoelous Caudal Vertebrae from the Early Late Cretaceous of Liaoning Province, China

We describe a new titanosaurian sauropod dinosaur, Borealosaurus wimani gen. et sp. nov., based on a distinctive mid-distal caudal vertebra from the early Late Cretaceous Sunjiawan Formation exposed in the Shuangmiao village of Beipiao in Liaoning, China. We provisionally refer an isolated tooth crown, a middle caudal vertebra, and a right humerus from the same locality and horizon to this taxon. Borealosaurus is distinguished from other sauropods in its possession of opisthocoelous mid-distal caudal vertebrae. The occurrence of opisthocoelous caudals in Borealosaurus and the Mongolian sauropod Opisthocoelicaudia raises the possibility that these taxa pertain to an as-yet unrecognized titanosaurian subclade endemic to the Cretaceous Asia.